JPH10326517A - Back surface lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of unevenness of luminance by arranging at least one or more cylindrical light sources in a bottom part inside of a flat lamp house, of which upper surface is opened, and arranging spacer pins in the bottom part inside of the lamp house except for parts provided with cylindrical light sources of a device having a light scattering body, which are arranged so as to seal the opening part of the lamp house. SOLUTION: At least one or more cylindrical light sources 1 are arranged in a bottom part inside of a flat lamp house 3, of which upper surface is opened, and spacer pins 4 are arranged in the bottom part inside of the lamp house except for parts provided with cylindrical light sources 1 of a back surface lighting device having a light scattering body 2, which are arranged so as to seal the opening of the lamp house 3. The spacer pin 4 is made of the white or transparent raw material, and desirably made of the resin. The spacer pins are desirably integrally formed with the lamp house 3. The number of the spacer pin 4 to be used depends on the screen size, and 4-6 pins are desirably formed in the screen at 12-16 inches, and 5-9 pins are desirably formed in the screen at 16-20 inches.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various display devices, and more particularly to a back light device for a word processor, a personal computer, a television, etc., and a back light device for a large liquid crystal display panel.

[0002]

2. Description of the Related Art Conventionally, in a rear illuminator using a cylindrical light source 1 such as a fluorescent tube, a direct light emitted from a cylindrical light source 1 and a light reflected in a lamp house 3 are reflected as shown in FIG. The light is incident on the light diffuser 2, the light is diffused in the light diffuser 2, and a uniform planar light is emitted from the upper surface of the light diffuser 2, which has been used as a light source of a liquid crystal display panel.

[0003]

However, in the conventional rear illuminating device as shown in FIG.
Is merely arranged in a closed manner at the opening of the lamp house 3, and the central part of the light diffuser 2 is
A slack is generated in the direction of the inner bottom portion, and the slack is approached to the cylindrical light source 1 to cause uneven brightness. In particular, in a large-size rear illuminating device, there is a disadvantage that the center of the light diffuser 2 sags toward the cylindrical light source 1 due to its own weight, causing luminance unevenness.

The present invention has been made as a result of earnest studies to solve this problem. By providing a spacer pin in a lamp house, the occurrence of the slack is eliminated.
The purpose is to improve luminance unevenness.

[0005]

According to the present invention, at least one or more cylindrical light sources 1 are arranged at the bottom of a flat lamp house 3 having a flat upper surface opening, and are arranged in a closed manner at the opening of the lamp house 3. In the rear illuminating device having the light diffuser 2, a lamp house 3 other than the place where the cylindrical light source 1 is arranged
The present invention is to provide a back illuminating device in which spacer pins 4 are arranged on the bottom of the inside.

[0006] By forming the spacer pins 4 of the present invention from a white or transparent material, particularly a resin, a more excellent back-lighting device can be obtained. Further, the spacer pins 4 can be formed integrally with the lamp house 3.

The number of spacer pins 4 used in the present invention varies depending on the screen size.
For 16 to 20 inches, 5 to 9 is an appropriate number.

[0008]

According to this structure, the light diffuser 2 is prevented from sagging toward the cylindrical light source 1, and a rear illuminating device with less luminance unevenness due to aging can be obtained.

[0009]

Embodiment 1 Hereinafter, a representative embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a screen size of 20 inches is adopted.
Is a light diffuser having a thickness of 2 mm, 3 is a lamp house, 4 is a truncated cone having a bottom surface of φ3.0 mm, an upper surface of φ1.0 mm, and an angle of 86.4 ° with a top surface of φ8.0 and a height of 1.1 mm. It shows a spacer pin having a shape arranged in the center.

As shown in the perspective view of FIG. 1, a plurality of spacer pins 4 are arranged at the bottom of the lamp house 3. By forming this spacer pin 4 from a white or transparent material, light absorption in the spacer pin 4 is reduced, and the tip is made sufficiently thin so that its shape is projected on the light diffuser 2. Blocked.

[0011]

Embodiment 2 The spacer pins 4 shown in the sectional view of FIG. 2 were made of white or transparent heat-resistant resin. By using a heat-resistant resin, it can be easily formed into an arbitrary shape, and at the same time, the weight can be reduced.

[0012]

Embodiment 3 A spacer pin 4 shown in the sectional view of FIG.

[0013]

By providing the spacer pins 4 in the lamp house 3, it is possible to prevent the occurrence of luminance unevenness caused by the central portion of the light diffuser 2 becoming slack due to its own weight on the side of the cylindrical light source 1 due to aging. You can do it. Therefore, even when the size of the rear illumination device is increased, almost no luminance unevenness due to a change over time is observed.

[Brief description of the drawings]

FIG. 1 is a perspective view of the rear illumination device of the present invention. FIG. 2 shows a sectional view of an embodiment of the present invention. FIG. 3 shows a sectional view of another embodiment of the present invention. FIG. 4 is a perspective view of a conventional rear lighting device.

[Explanation of symbols]

 1: cylindrical light source 2: light diffuser 3: lamp house 4: spacer pin

Claims (4)

[Claims] 1. A rear illuminating device having at least one or more cylindrical light sources disposed at a bottom of a flat lamp house having an upper opening and a light diffuser disposed in a closed manner at an opening of the lamp house. A rear illuminating device, wherein spacer pins are arranged on the bottom of the lamp house other than where the cylindrical light source is arranged. 2. A back illuminator according to claim 1, wherein said spacer pin is made of a white or transparent material. 3. A back illuminator, wherein the spacer pin according to claim 1 is made of resin. 4. A rear illuminating device in which the spacer pin according to claim 1 is integrated with a lamp house.